title: Long-term outcome of gradual reduction using overhead traction for developmental dysplasia of the hip over 6 months of age.
abstract: BACKGROUND
  In children over 6 months of age with developmental dysplasia of the hip (DDH), achieving a concentrically reduced hip while avoiding avascular necrosis (AVN) is challenging. The utility of gradual reduction (GR) using traction has insufficient evidence. We therefore report the long-term outcome of GR using overhead traction (OHT).
  
  
  METHODS
  We retrospectively reviewed 67 patients with DDH (75 hips) treated with GR using OHT over 6 months of age. The age at reduction ranged from 7 months to 4 years. All patients were followed up until skeletal maturity with a mean duration of 15.6 years. Pelvic radiographs were used to assess AVN, acetabular development, and the Severin classification. We determined the factors affecting the outcome at skeletal maturity.
  
  
  RESULTS
  Seventy-two hips (96%) were successfully reduced, 2 required subsequent closed reduction and 1 underwent open reduction. AVN occurred in 2 hips (2.7%). Among 48 hips (64%) with residual acetabular dysplasia, 31 were treated with Salter innominate osteotomy (SIO) between 5 and 6 years of age. Finally, 62 hips (82.7%) showed satisfactory outcome (56 in Severin class I and 6 in class II), whereas 13 showed unsatisfactory outcome (class III). Although we found no significant factors affecting the outcome, most of the hips treated with SIO were included in the satisfactory group.
  
  
  CONCLUSIONS
  GR using OHT could effectively minimize the risk of developing AVN in patients with DDH over 6 months of age at presentation. SIO at preschool age may play a beneficial role in the long-term outcome of GR using OHT.
authors.affiliation: Department of Orthopaedic Surgery, Nagoya University Graduate School of Medicine, Nagoya, Aichi, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kaneko
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kitoh
authors.forename: Kenichi
authors.initials: K
authors.lastname: Mishima
authors.forename: Masaki
authors.initials: M
authors.lastname: Matsushita
authors.forename: Naoki
authors.initials: N
authors.lastname: Ishiguro
mesh_terms: D000077:Acetabulum / Q000378:metabolism / Q000473:pathology; D000365:Age Determination by Skeleton; D002675:Child, Preschool; D005260:Female; D005500:Follow-Up Studies; D006618:Hip Dislocation, Congenital / Q000628:therapy*; D006801:Humans; D007223:Infant; D008297:Male; D010020:Osteonecrosis / Q000453:epidemiology*; D010027:Osteotomy / Q000379:methods*; D012189:Retrospective Studies; D013997:Time Factors; D014143:Traction / Q000379:methods*; D016896:Treatment Outcome